Finns have once again been ranked first in the World Happiness index, while Afghans dropped to the bottom of the global table, earlier occupied by Sudan.

The clergy-dominated Iran finished at 118th, the U.S.A. 18th, and Tajikistan on 106th spot, the report says.

The World Happiness Report (WHR) says it is a landmark survey of the state of global happiness that ranks 156 countries by how happy their citizens perceive themselves to be.

WHR's latest report on March 20 shows that Nordic countries have dominated the top ten, followed by Switzerland, New Zealand, and Austria. Luxembourg also edged into the tenth spot for the first time this year.

For the first time, the WHR 2020 has also ranked cities around the world by their "subjective well-being" and digging more deeply into how the social, urban, and natural environments combine to affect people's happiness.

The capital city of Finland, Helsinki, ranked first, while Afghanistan's capital city, Kabul, dropped to the bottom of the table.

Iranian capital city, Tehran, and the country's second-largest city, Mashhad, finished at 155th and 156th place, respectively.

WHR says that its urban ranking relies on city residents' self-reports of how they evaluate the quality of their lives, adding, in doing so, it emancipates respondents to consider and weigh for themselves which factors – observable or unobservable to researchers – they feel matter most to them.

According to the report, about 4.2 billion people, more than half of the world's population (55.3 percent), are living in urban areas today. By 2045, this figure is estimated to increase by 1.5 times, to more than six billion. There were 371 cities with more than one million inhabitants at the turn of the century in 2000.

Last year, the Islamic Republic of Iran finished at 117th in the WHR table, eleven positions below its spots in 2018.

Based on the 2020 report Iran has dropped to one spot below its 2019 position, finishing 118th.